Hi @futuradv, thanks for your question.
Wordfence is unintrusive and generally runs well on the vast majority of ~5m sites it’s installed on despite having to consider many server and plugin/theme combinations. We constantly work on making the plugin faster, perform better, and use less resources but there are not set amounts of RAM, CPU or database queries that we know Wordfence will definitely require in each use-case or hosting environment. Shared hosting, larger databases, or more installed plugins could all be a factor in slower operation in specific cases.
Aside from this, if?Litespeed?or Cloudflare run on your server, you could check if their configuration with Wordfence is contributing in any way to the slow-down of your site. Cloudflare for example requires a bespoke Wordfence IP detection option selecting, and whitelisting of your own server’s IP in their settings for scans to run correctly. Litespeed requires a noabort
setting to prevent scans from stopping whilst in progress.
Let us know if you see anything specific in your server/PHP/database logs that might point to Wordfence as we could make further suggestions based on the kind of specific errors or messages you’re seeing.
Thanks,
Peter.